The energetic cost of response to blue‐green algal filaments by cladocerans1

Specific differences in behavior and energy expenditure in response to blue‐green algal filaments were examined as a possible cause of the shift from large‐ to small‐bodied cladocerans during eutrophication and seasonal succession. Mandible rate increased with body size among species and was maximal and independent of filament concentration within a species. Carapace gape increased with body size among species and was independent of filament concentration for Daphnia parvula, Ceriodaphnia lacustris, and Bosmina longirostris while it decreased with increasing concentration for Daphnia magna. An increase in Anabaena filament concentration caused a significant increase in rejection and respiration rates only for the largest species, D. parvula.